Heretofore, a system to display stereoscopic image by imaging a common subject by two video cameras from the right and left at the same time, and presenting the obtained image to each of right and left eyes, is known. However, with such a system, the device is large and not only mobility is lacking, but also shift of the optical axis of the right and left cameras easily happens, and obtaining image with appropriate disparity has been difficult.
For example, there are some cases where an interval between two cameras becomes great, or the right and left optical axes are shifted during zooming due to individual difference of the lenses of the cameras, or the right and left screen size not being the same. Also, there have been other cases in that, at the time of focus operating, during operation of directing the right and left video cameras toward the subject, i.e., when performing convergence operations, right and left video cameras shift vertically.
If such shift in optical axes or the like occurs between right and left cameras, it forces the optical system of a user who is viewing stereoscopic images to perform information processing different from what is experienced in normal life, so this is a factor of visual fatigue. Further, when the user superimposes and views the right and left image without using glasses for stereopsis, the video appears unnatural since the subject looks double.
Accordingly, an imaging apparatus has been proposed such that, with a region serving as the pupil of a lens, light from a subject is divided into two light fluxes by a mirror and imaging is performed (see PTL 1, for example). With this imaging apparatus, by performing imaging with each of the two divided light fluxes, disparity information of the subject can be obtained and at the same time, an image for stereopsis to present to the right and left eyes can be obtained.